Aircraft wing structures include fixed members as well as various moving control surfaces such as ailerons, flaps, and the like which, during certain flight conditions, can give rise to drag, vortex noise, and other undesirable effects. For example, when a wing flap is extended relative to the fixed wing structure, a strong vortex is typically generated by the resulting gap between the flap and the wing.
Prior solutions have attempted to address this flap vortex problem by incorporating unitary vertical fence structures into, for example, the outboard flap itself or on the fixed wing structure. Such designs, while moderately effective, are nonetheless undesirable in that, to make them completely close the gap off at a full flap extended position, the fence extends far out into the airflow, thus greatly increasing drag and weight. If the fence is designed to cover only the less-extended flap settings, then a significant gap remains between the flap and wing structure, producing significant vortex noise and reducing lift. Furthermore, increasing the surface of the flap fence can increase the drag produced by the structure during cruise conditions.
Accordingly, it is desirable to provide a flap fence design that reduces vortex noise while not significantly increasing drag. Furthermore, other desirable features and characteristics of the various embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.